Solid-State Imaging Device, Method for Driving Solid-State Imaging Device, and Electronic Apparatus

1. A solid-state imaging device comprising: a pixel part having a plurality of pixels arranged in a matrix pattern, the pixels having a photoelectric converting function; a reading part for reading a pixel signal from the pixel part; and a response data generating part including a fuzzy extractor, the response data generating part generating response data including a unique key in association with at least one selected from the group consisting of variation information of the pixels and variation information of the reading part, wherein the fuzzy extractor includes: an initial key generating part including a true random number generator arranged to correspond to a column output from the pixel part or a pixel signal read from the pixels by the reading part in a true random number generation mode, the true random number generator generating a true random number using a read-out signal read from a column signal processing part of the reading part, the column signal processing part processing a column output signal input thereto, the initial key generating part generating an initial key and helper data based on the true random number generated by the true random number generator and based on the variation information acquired as a response when the initial key is generated; and a key regenerating part for generating, when a key is regenerated, a unique key based on the helper data acquired by generating the initial key and based on variation information acquired as a response including an error when the key is regenerated.

2. The solid-state imaging device according to claim 1 , wherein the pixels have: a photoelectric conversion element for storing therein, in a storing period, charges generated by photoelectric conversion; a transfer element for transferring, in a transfer period, the charges stored in the photoelectric conversion element; a floating diffusion (FD) to which the charges stored in the photoelectric conversion element are transferred through the transfer element; a source follower element for converting the charges in the floating diffusion into a voltage signal with a gain determined by the quantity of the charges; and a reset element for resetting the floating diffusion to a predetermined potential, and wherein the pixel signal read from the pixels by the reading part in the true random number generation mode includes: a signal containing FD reset noise observed while the reset element is in a conduction state; or a signal containing FD reset noise observed while the reset element and the transfer element are in a conduction state.

3. The solid-state imaging device according to claim 2 , wherein the pixel part has a pixel sharing configuration in such a manner that one floating diffusion, one source follower element and one reset element are shared between a plurality of photoelectric conversion elements and a plurality of transfer elements.

4. The solid-state imaging device according to claim 2 , wherein a clip circuit is provided at an end of an array of the pixels for limiting a pixel output voltage amplitude.

5. The solid-state imaging device according to claim 1 , wherein the reading part reads the pixel signal or the read-out signal multiple times in the true random number generation mode.

6. The solid-state imaging device according to claim 5 , wherein the reading part reads the pixel signal from a selected one of the pixels multiple times.

7. The solid-state imaging device according to claim 5 , wherein the reading part reads the pixel signal from a plurality of pixels in a selected row.

8. The solid-state imaging device according to claim 5 , wherein the reading part reads the pixel signal from a plurality of pixels in a selected column.

9. The solid-state imaging device according to claim 8 , wherein the reading part includes: a plurality of column signal processing parts each arranged to correspond to at least one column output from the pixel part, each column signal processing part processing a column output signal input thereto; and a multiplexer for shuffling destinations of column output signals of column outputs from the pixel part such that a given column output signal of a given column output is input into a column signal processing part different from an intended column signal processing part arranged to correspond to the given column output.

10. The solid-state imaging device according to claim 2 , wherein a pixel to be read in the true random number generation mode is selected from pixels arranged in an optical black region.

11. The solid-state imaging device according to claim 1 , wherein a column signal processing part of the reading part includes: an amplifier for amplifying a read-out signal from the pixels; and an analog-to-digital (AD) converter for analog-to-digital converting an output signal from the amplifier, and wherein a read-out signal from the column signal processing part of the reading part includes: an output signal from the AD converter while no read-out signal is input from the pixels into the amplifier and while no output is input into the AD converter from the amplifier; or an output signal from the AD converter while no read-out signal is input from the pixels into the amplifier and while output from the amplifier is input into the AD converter.

12. The solid-state imaging device according to claim 1 , wherein the true random number generator performs an exclusive logical OR operation on a plurality of pixel signals or a plurality of read-out signals.

13. The solid-state imaging device according to claim 1 , wherein, in the fuzzy extractor, the initial key generating part generates the initial key and the helper data based on the variation information acquired as a response when the initial key is generated, and when a key is regenerated, the key regenerating part generates a unique key in a soft-decision manner using the helper data acquired by generating the initial key, variation information acquired as a response including an error when the key is regenerated, and reliability information determined based on the variation information when the key is regenerated.

14. A method for driving a solid-state imaging device, the solid-state imaging device including: a pixel part having a plurality of pixels arranged in a matrix pattern, the pixels having a photoelectric converting function; and a reading part for reading a pixel signal from the pixel part, wherein the method comprises steps of: acquiring at least one selected from the group consisting of variation information of the pixels and variation information of the reading part; and generating response data including a unique key in association with the variation information acquired in the acquiring step, the response data generating step including fuzzy extraction performed using a fuzzy extractor, and wherein the fuzzy extraction included in the response data generating step includes steps of: generating an initial key and helper data, the initial key generating step including a step of generating a true random number using a read-out signal read from a column signal processing part of the reading part, the column signal processing part processing a column output signal input thereto, by a true random number generator arranged to correspond to a column output from the pixel part or a pixel signal read from the pixels by the reading part in a true random number generation mode, the initial key and the helper data being generated based on the true random number generated in the true random number generating step and based on the variation information acquired as a response when the initial key is generated; and when a key is regenerated, generating a unique key based on the helper data acquired by generating the initial key and based on variation information acquired as a response including an error when the key is regenerated.

15. An electronic apparatus comprising: a solid-state imaging device; and an optical system for forming a subject image on the solid-state imaging device, wherein the solid-state imaging device includes: a pixel part having a plurality of pixels arranged in a matrix pattern, the pixels having a photoelectric converting function; a reading part for reading a pixel signal from the pixel part; and a response data generating part including a fuzzy extractor, the response data generating part generating response data including a unique key in association with at least one selected from the group consisting of variation information of the pixels and variation information of the reading part, and wherein the fuzzy extractor includes: an initial key generating part including a true random number generator arranged to correspond to a column output from the pixel part or a pixel signal read from the pixels by the reading part in a true random number generation mode, the true random number generator generating a true random number using a read-out signal read from a column signal processing part of the reading part, the column signal processing part processing a column output signal input thereto, the initial key generating part generating an initial key and helper data based on the true random number generated by the true random number generator and based on the variation information acquired as a response when the initial key is generated; and a key regenerating part for generating, when a key is regenerated, a unique key based on the helper data acquired by generating the initial key and based on variation information acquired as a response including an error when the key is regenerated.